Crystal holder



Nov. 22, 1949 REEVES 2,488,781

' CRYSTAL HOLDER Filed Sept. 28, 1945 FlG.| F|G.2 FIG.3

FIG.7

INVENTOR.

HAZARD E.REEVES FIG.4 BY 2 ATTORNEY Patented Nov. 22, 1949 CRYSTAL HOLDER Hazard Earle Reeves, New York, N..Y., assignor,

by mcsne assignments, to'Reeves Hoffman Corporation, Carlisle, Pa., a corporation of Pennsylvania Application September 28, 1945, Serial No. 619,180

6 Claims. 1 This invention relates to new and useful improvements in holders for piezoelectric oscillators.

The objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein satisfactory embodiments of the invention are shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such Variations and modifications as fall within the spirit of the invention and the scope of the appended claims.

In the drawing:

Fig. 1 is an end elevational view, on a greatly enlarged scale, of a crystal holder made in accordance with the invention;

Fig. 2 is a central longitudinal sectional view therethrough taken as along the line 22 of Fig. 1;

Fig. 3 is a sectional view as along the line 3--3 of Fig. 2, one of the closure caps being omitted;

Fig. 4 is a perspective View showing the crystal holder with one end open and with the closure for such end about to be applied;

Fig. 5 is a view similar to Fig. 1 but showing a slight modification;

Fig. 6 is a central sectional view as along the line 66 of Fig. 5; and

Fig. '7 is a sectional view as along the line of Fi 6.

Referring in detail to the drawing and at first more particularly to the device shown in Figs. 1

through 4, the holder there disclosed comprises a relatively short tubular body In formed of glass or of other insulating material impervious to moisture. Body I0 is shown as externally threaded at its respective ends as at H and i2 and as closed by metallic caps l3 and H.

Interposed between the caps I3 and I4 and the respective ends of the body ID are washers or gaskets l5 and [6 of compressible materials, as for example natural rubber or some synthetic or artificial elastomer. Within the body i0 is an oscillator l! as for example of quartz. This oscillator is located between electrodes l8 and I9. Coil springs 20 and 2i bear against the outer sides of the electrodes I8 and I9 respectively, forcing such electrodes against the oscillator H. In addition to bearing against the electrodes at their inner ends, the springs 20 and 2|, at their outer ends, bear against the caps or closures l3 and [4.

Thus it will be seen that the coil springs, in

addition to functioning as a means pressing the electrodes against the oscillator, also function as conductors between the electrodes and the caps 13 and Hi. If desired, and to secure good electrical contact, the respective ends of the respective springs may be carried partly across the respective electrodes and caps as suggested by the spring end 22. To provide for a minimum of contact of the oscillator and electrodes with the body 10, the latter may be provided with a series of radially spaced longitudinall extending ribs 23 on its inner surface. With this arrangement the electrodes and the oscillator will have tangential engagement only with the ribs 23.

With the described construction one of the closures, as, for example, cap [3 may be threaded into place on the body l0. Thereafter spring 20, electrode l8, oscillator l1, electrode [9 and spring 2| are positioned or partly positioned in the body In and the cap or closure I4 is threaded into place (see Fig. 4). Each of the end closures or caps l3 and i4 is externally knurled or serrated as at 24. Therefore when both caps are in place as above described, a further tightening of the caps, which may be manually accomplished since the caps are knurled to give a better grip, the washers or gaskets l5 and I6 are compressed so that a hermetic seal is established within the holder.

The electrodes I8 and ii) are electrically connected with the caps or closures l3 and [4 respectively and any desired connections between said caps and other apparatus may readily be made. While the caps are shown as formed entirely of metal it will be understood that this is not an absolute limitation since the caps may be partly of metal or may be entirely of an insulating material provided with suitable contacts for engagement with the springs.

From the above description taken in connection with the drawing it will be apparent that I have provided a very inexpensive construction of crystal holder. The same comprises merely the body In and a pair of end caps. The body i0 is merely a glass cylinder having a thread molded thereon at each end. Thus'the body is inexpensive to make. The caps are also of inexpensive construction, being merely closure caps of more or less conventional form. With one cap in place parts are easily assembled in the body and thereafter the other cap is applied and its application results in a compression of the springs 20 and 2|.

As'the respective ends of the body are oppositely threaded and the caps are knurled to give a good grip, it will be apparent that a final tightening of the caps may be manually given to compress the gaskets or washers II and II and establish an air-tight seal. As the body is of glass and the closures of metal, it will be apparent that all exposed parts are impervious to moisture and that moisture cannot enter the device even though the latter be submerged for a great I eriod of time.

Referring now to Figs. 5 through 7, the device there shown comprises a body of glass or other insulating material generally designated 2!, cppositely threaded at its respective ends and at such ends mounting a pair of metal caps or closures 23 and 21 respectively. The body I! is shown as externally cylindrical but it will be understood that this is a matter of convenience. Internally the body has a substantially rectangular opening at 23 therethrough and such opening mounts a similarly shaped oscillator 23, for example of quartz, having electrodes 30 and 3! plated on its opposite surfaces.

Solder 32 connects a conductor 33 with electrode 30 while solder 34 connects a similar condoctor 35 with electrode 3|. These conductors or wires 33 and 35 are carried outwardly through prepared openings in the closures 26 and 21 and then the material of such closures about such openings is pinched in against the conductors as at 30 and 31 respectively. If desired, solder may also be applied where the respective conductors go through the respective caps to insure that a hermetic seal will be established at these places.

Compressible gaskets 38 and 33 corresponding with the gaskets l5 and I6 of the figures first described are also introduced between the ends of the body 25 and the caps 26 and 21. These gaskets, as in the case of the gaskets i5 and It, may be carried by the respective caps so that there is no assembly problem involved in the use of the gaskets.

In assembling the device of Figs. 5, 6 and 7.

the conductors are soldered to the respective electrodes. Thereafter such sub-assembly is positioned in the body through one end thereof and one of the caps, for example cap 25, is threaded tight into place with the conductor 33 passing through the centrally located openin in the cap. When the cap is tight in place it is pinched at 36 about the conductor and a drop of solder may be added, if desired, to insure a seal. This serves to locate the oscillator and electrode and conductors with respect to the body 25. Now the cap 21 is threaded into place and tightened on the body, the conductor 35 extending through the central opening in the cap. When the cap is tight in place its portion 31 is pinched against the conductor 35 and, if desired, a drop of solder added to insure a seal. Internally the body 25 is provided with four diagonally opposite grooves 38 adapted to receive the corner portions of electrodes and oscillators when such an arrangement is desired.

Having thus set forth the nature of my invention. what I claim is:

1. In a piezoelectric device a tubular body open at its respective ends, said body being externally threaded in opposite directions on its respective ends, an oscillator within said body, an electrode against each side of said oscillator, threaded metallic closures screwed on the respective ends of said body. and 00.1 springs positioned within said body and each bearing against the inner side of one of said closures and the outer side of one of said electrodes.

2. A piezoelectric device comprising a hollow body of glass open at its opposite ends, said body being oppositely threaded at its respective ends, an oscillator in said body, an electrode against each side of said oscillator, threaded closures screwed to the respective ends of said body, a conductor between one of said electrodes and one\o1 said closures, spaced longitudinally extending' ribs on the inner surface of said body, and said oscillator and electrodes being supported within the body by engagement of portions of their-edges with said ribs.

3. In a piezoelectric device, an oscillator, an electrode at each side of said oscillator, a tubular body of insulating material open through both its ends, said oscillator and electrodes being positioned within the body intermediate the ends of the latter and at right angles to its central axis, a metal closure on each end of the body, and said electrodes being electrically connected with the respective closures.

4. In a piezoelectric device, an oscillator, an electrode at each side of said oscillator, an externally threaded tubular body of insulating materlal open through both its ends, said osci1- labor and electrodes being positioned within the body intermediate the ends of the latter and at right angles to its central axis, threaded metal closures screwed on each end of the body, and a conductor between one of said electrodes and one 01' said closures.

5. In a pie oelectric device, an oscillator, an electrode at ach side of said oscillator, a tubular body of insulating material open through both its ends, said body externally being threaded in opposite directions on its respective ends, said oscillator and electrodes being positioned within the body intermediate the ends of the latter and at right angles to its central axis, threaded metal closures screwed on the respective ends of the body, compressible gaskets between said closures and the respective ends of said body whereby when the closures are screwed into place said gaskets are compressed and seals established, and said electrodes being electrically connected with the respective closures.

6. In a piezoelectric device, an oscillator, an electrode at each side of said oscillator, a tubular body of insulating material open through both its ends, said oscillator and electrodes being positioned within the body intermediate the ends of the latter and at right angles to its central axis, a conductor secured to each of said electrodes and extending outwardly therefrom toward the opposite ends of said body, metal 010- sures on the respective ends of said body, and said electrodes being mechanically connected with the respective closures.

HAZARD EARLE REEVES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nelson Nov. 11, 1947 

